The invention relates to the field of wireless data communication, and particularly a system based on digital wireless telephone systems technology such as the standardised Digital Enhanced Cordless Telecommunication (DECT) and operating according to the Wireless Application Protocol (WAP) for providing access to local data applications and data files on a private xe2x80x9chomexe2x80x9d WAP gateway.
Without getting as much attention as cellular phones, cordless telephones (CT) are becoming widespread consumer products, and they are paving the way towards ubiquitous low cost personal communications networks. The cordless telephone systems were first manufactured and made commercially available in 1980s. They operate solely as an extension telephones to a transceiver connected to a subscriber line on the public telephone network (PTN) and are primarily for in-home use. They enhance fixed telephones by offering more freedom and higher mobility degree, i.e. allowing the user to operate in a wider area. Cordless telephone systems are generally full duplex communication systems that use radio to connect a portable handset to a dedicated base station, which is then connected to a telephone line associated with a specific telephone number on the public telephone network (PTN). In the first generation, the portable unit communicates only to the dedicated base unit and only over distances of a few tens of meters. Cordless telephone systems provide the user with limited range and mobility, as it is usually not possible to maintain a call if the user travels outside the range of the base station. Typical second generation base stations provide coverage ranges up to a few hundred meters. FIG. 1 illustrates a typical state-of-the-art cordless telephone system.
CT2 is a digital version of the first generation, analogue cordless telephones, introduced in Great Britain. When compared with analogue cordless phones, CT2 offers good speed quality, is more resistant to interference, noise, and fading, and like other personal telephones, uses a compact handset with built-in antenna. The Digital European Cordless Telephone (DECT), later renamed to Digital Enhanced Cordless Telecommunication, is a universal cordless telephone Standard developed by the European Telecommunications Standards Institute (ETSI), issued in 1992.
The Problem Areas
Although digital cordless telephone standards such as DECT specify both voice and data applications, they are limited to the bearer level, that is the ISO-OSI physical and data link layers (layers 1 and 2) and are not sufficient to enable data applications on the handset (or portable unit).
Known Solutions and Problems with These
Generally, existing cordless telephone systems on the market allow only voice communication services on the handsets. Such a limitation is expected soon to be intolerable by the market now that the WAP enabled cellular phones are being launched. The need for a solution enabling access to data and applications both on the world wide web and locally on a PC or workstation via cordless telephone is getting more and more urgent. With the advent of the Internet and the arrival of new generation of handsets having larger displays, the demand for data applications for cordless telephone systems is imminent.
There are some activities in the xe2x80x9cWAP Forumxe2x80x9d aiming to define DECT as an access technology enabling WAP, and to specify how to implement it. A description in this regard is given in the document xe2x80x9cCR to WAPxe2x80x9d of May 29, 1999, Change Request to WAP Forum Ltd, San Francisco, by Arjan te Marvelde, Ericsson, and Dr. G. Kelnhofer, Siemens. However, these activities have focus on the protocol level, i.e. how should the protocol stacks be for different units (handset, Fixed part, WAP gateway, etc.). The main architecture for WAP over DECT is the standard WAP architecture where the public WAP gateway is own and administered by a network operator or a service provider. Such a WAP gateway will also serve a number of users having subscription to the network operator or service provider. As shown in FIG. 2, in the xe2x80x9cWAP over DECTxe2x80x9d architecture the user via his DECT handset can have access to a WEB/WAP server via a public WAP gateway. Such a solution will allow the DECT users to access data and applications residing on remote computers or servers which are in the World Wide Web. However, the architecture does not give direct local access to data and applications residing on a local PC or workstation.
At present the applicant is not aware of any solution that enables access to both data and applications on the web and those residing on a local PC or workstation via cordless telephone handsets.
It is an object of the present invention to extend the xe2x80x9cWAP over DECTxe2x80x9d architecture and thereby allow access from cordless telephone handsets to data and applications on the web as well as those residing on a local PC or workstation.
It is a further object of the present invention to propose a way to obviate the limitation in current cordless telephone systems and to enable all data application types, ranging from Web content access to management of the cordless telephone system itself by means of the Wireless Application Protocol (WAP).
In order to enable data applications on digital cordless telephone systems which can be CT2, DECT or others, this invention promotes the introduction of the Wireless Application Protocol (WAP) in a single base station cordless telephone system. The invention proposes a new architecture for home WAP where a PC-based private WAP gateway is introduced. The private WAP gateway may be owned and administered by the user or user organisation as in the case of a small office or a private home. Such a private WAP gateway allows the user to have access to data applications located locally in his PC as well as those residing on a WEB/WAP server on the Internet.
The objects of the invention are met by a system comprising at least one local PC or similar computer device serving as a local WAP gateway, at least one DECT bases station, and one or more DECT handsets adapted to wireless communication with said at least one base station, wherein the DECT base station is connected to the local WAP server and optionally to a public communications network, the system further comprising a switching function for routing information traffic between the DECT handset and the selected WAP gateway.